This invention relates to an electric arrangement for igniting and supplying a gas discharge lamp, which arrangement has two input terminals for connection to an AC power supply source A, rectifier bridge connected to the AC power supply source has output terminals connected to a DC/AC converter having two input terminals, one terminal of which is connected to the other terminal at least via a series arrangement of a first semiconductor switching element and a load circuit comprising at least an induction coil and the discharge lamp as well as a capacitor. The load circuit and capacitor are shunted by a circuit comprising a second semiconductor switching element and a third semiconductor switching element, the first two semiconductor switching elements being shunted by a buffer capacitor. An arrangement of this type is known from the published British Patent Application No. 2,124,042.
This British Patent Application describes a high-frequency ballast circuit for a gas discharge lamp comprising a DC/AC converter of the half bridge or full bridge type. The circuit is designed in such a way that during operation, charge current peaks of the buffer capacitor in the mains power supply are suppressed without using special filters (such as bulky choke coils). This is possible by charging the buffer capacitor to a voltage exceeding the peak of the mains voltage.
It has been found that a reasonable suppression of the said current peaks can be realized only in a specific combination of a lamp having a given power and the associated specific values of electric components incorporated in the circuit. An adaptation of the values of the said components is necessary for operating a lamp having a different power. This is a drawback because such circuits then cannot easily be used universally for lamps having different powers.